pub mod nation {
    pub mod government {
        pub fn govern() {
			 println!("Hello, China!");
		}
    }

    mod congress {
        pub fn legislate() {
            println!("Hello, congress!");
        }
    }
    
    mod court {
        fn judicial() {
            super::congress::legislate();
        }
    }
}
// 如果其他模块引用了就不需要use 了
//use crate::nation::government::govern;
 //use crate::nation::nation::government::govern;
//fn main() {
  //  nation::government::govern();
//}